Can my boss in a public corporate chat, where all employees can see what happens, mention that I made mistakes that are basic foundational ones? Besides that, also in the same chat, he mentioned regarding a topic we were discussing, that "I doubt it is right"

Thank you for your question. We will need additional details to properly assess your situation. However, it is important that you put your position to the Company in writing. If you disagree with what was said, write an email, outlining why. Be respectful and non-confrontational, yet firm. If you would like to provide additional details, please contact us at the number below to schedule a formal consultation.